Railway-traffic-controlling apparatus



L. V. LEWIS.

RAILWAY TRAFFIC CONTROLLING APPARATUS. APPLICATION FILED AUG. 15, 1919. RENEWED FEB.27,1922.

1 ,428,894;, PatentedSept. 12, 1922.

6 $HEETSSHEET 1. HF

INVENTOR. W

BY Q: X M

e ATTORNEY.

L. V. LEWIS.

RAILWAY TRAFFIC CONTROLLING APPARATUS.

APPLICATION FILED Au/alw, 1919. RENEWED FEB. 21, 1922.

PatentedSept. 12, 1922.

6 SHEETSSHEET 2.

R. X m w ML H m m m a m 4 n i X Q N 0 Y am B INN NNKEW U w M R QWMN ZWN Qw 2 mm L. V. LEWIS.

RAILWAY TRAFFIC CONTROLLING APPARATUS.

APPLICATION FILED AUG. 15, 1919. RENEWED FEB. 27, 1922.

Patented Sept. 12, 1922.

INVENTOR.

6 SHEETS-SHEET 3.

M ATTORNEY L. V. LEWIS.

RALLWAY TRAFFIC CONTROLLING APPARATUS.

APPLICATION FILED AUG-l5, I919- RENEWED FEB. 27, I922.

1,428,894, PatentedSept. 12, 1922.

6 SHEETSSHEE1 4.

L. V. LEWIS.

RAILWAY TRAFFIC CONTROLLING APPARATUS.

APPLICATION FILED AUG.I5, 1919. RENEWED FEB.

21, I922. Patented Sept. 12, 1922.

6 SHEETS-SHEET 5.

L. V. LEWIS.

RAILWAY TRAFFIC CONTROLUNGAPPARATUS. APPLICATION FILED AUG. [5, 1919. RENEWED FEB.

27, 1922. PatentedSept. 12, 1922.

s SHEETS-SHEET a.

Patented Sept. 12, 1922.

UNITED STATES PATENT OFFICE.

LLOYD V. LEWIS, OF EDGEWOOD BOROUGH, PENNSYLVANIA, ASSIGNOR TO THE UNION SWITCH & SIGNAL COMPANY, OF SWISSVALE, PENNSYLVANIA, A COR- POMTION OF PENNSYLVANIA.

RAILWAY-TRAFFIC-CONTROLLING APPARATUS.

Application filed August 15, 1919, Serial No. 317,830. Renewed February 27, 1922. Serial No. 589,765.

To all whom it, may concern:

Be it known that I, LLOYD V. LEWIS, a citizen of the United States, residing at Edgewood Borough, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Railway-Traflic-Controlling Apparatus, of which the following is a specification.

My invention relates to railway traflic controlling apparatus of the type in which traflic governing means located on a railway car or train is controlled by energy received from the track rails.

One feature of my invention is the provision of a system of this character which is adapted for use in connection with direct current track circuits of the usual type.

I will describe several forms of system embodying my invention, and will then point out the novel features thereof in claims.

In the accompanying drawings, Fi 1 is a diagrammatic view showing one orm and arrangement of track-way apparatus embodying my invention and adapted particularly for use on a track over which traffic normally moves in one direction only. Fig. 2 is a diagrammatic view showing one form of vehicle carried apparatus embodying my invention and adapted for cooperation with the trackway apparatus shown in Fig. 1. Fig. 3 is a view showing a modification of the vehicle carried apparatus shown in Fig. 2 and also embodying my invention. Figs. 4, 4 and 4 are diagrammatic views which when placed end to end in the order named, show one form of trackway apparatus adapted for use on single track railways over which traffic moves in both directions, and also embodying my invention.

Similar reference characters refer to similar parts in each of the several views.

Referring first to Fig. 1, the reference characters 1 and 1 designate the track rails of a railway over which traffic normally moves in the direction indicated by the arrow. These rails are divided by insulated joints 7 into a plurality of blocks, of which only two complete blocks AB and B-C are shown in the drawing.

Each block is provided with a track circuit comprising as usual the track rails of the block, a source of current connected across the rails at the exit end of the block,

and a track relay connected across the rails at the entrance end of the block. As here shown, the source of current for each track circuit is a battery designated by the reference character D with an exponent corresponding to the particular location, this battery being reversibly connected with the rails by a pole-changer designated P with a suitable exponent. The track relay for each block is designated H with an exponent corresponding to the location, each of these relays, of course, being adapted for operation by direct current. Each track relay is of a polarized type, comprising two neutral armature contacts 2 and 8 and a polarized armature contact 4. It follows, of course, that. the polarized contact 4 will be swung in one direction or the other according as the pole-changer for the corresponding track circuit is in one position or the other, and that the neutral contacts 2 and 8 of each relay will be closed or opened according as the relay is energized or deenergized.

Located adjacent the entrance end of each block is a roadside signal designated by the reference character S with an exponent corresponding to the location. Each of these signals, as here shown, is of the semaphore type adapted to indicate stop, caution or proceed according as the semaphore is in the horizontal, the inclined or the vertical position. Each signal is controlled by the track relay for the corresponding block through the medium of a caution indication circuit and a proceed indication circuit. Considering signal S, for example the caution indication circuit is from one terminal B of a suitable source of current such as a battery, through the neutral contact 2 of relay H wire 3, and the operating mechanism of signal S to the other terminal 0 of the same source of current. The proceed indication circuit for this signal (shown open in the drawing) is from battery terminal B, through contact 2, polarized contact 4, wire 5, and the operating mechanism of signal S, to the other battery terminal 0. This proceed indication circuit is closed only when polarized contact 4is swung to the left, and this occurs only when the relay H is supplied with current of what I will term normal polarity. When the relay is supplied With current of the opposite or reverse polarity, contact 4 is open as shown, so that the signal indicates caution.

The pole-changer P, which is included in each track circuit, is operated by the signal S for the block next in advance, and in such manner that the polarity of the current supplied to the track circuit is normal when the signal indicates proceed or caution, and reverse. when the signal indicates stop.

The operation of the apparatus thus far described is in accordance with usual and standard practice, and hence it is so well understood that no explanation is necessary.

For each block I have provided means for connecting a source of alternating vehicle governing current across the rails at the exit end of the block in series with the track battery for the block. As here shown, this means comprises a transformer designated by the reference character T with an ex-- ponent corresponding to the location, the secondary of which is included in the connection between the lower track rail 1 and the track battery D. The primary of each transformer T is at times connected with a transmission line E, which is supplied with alternating vehicle governing current by a suitable generator F. The primary circuit of each transformer T includes the neutral contact 8 of the track relay for the block next in advance, so that vehicle governing current is supplied to the rails of each block when the track relay for the block next in advance is energized, but not when such track relay is deenergized. In other words, this current is supplied to each block'only when the block next in advance is unoccupied.

In accordance with usual practice, anoninductivev resistance 6 is interposed inthe connection between the track rail 1 and the secondary of transformer T to limit the current drawn from this transformer andfrom the battery D when a car or train is near the exit end of the block.

Referring now to Fig. 2, the vehicle carried apparatus in the form shown herein includes two laminated soft iron cores 9 and 9, mounted on the vehicle in advance of the forward axle and located over the two track rails 1 and 1 respectively. Each of these cores is U-shaped, with its legs pointing downwardly, and each core is disposed transversely with respect to the rail. The two cores 9 and 9 are provided with windings 10 and 10, respectively. It is apparent, therefore, that when alternating current flows in either rail, part of the magnetic lines of force surrounding such rail will pass through the core which is directly over the rail, and so will induce an alternating potential in the coil carried by such core.

vBy

The two coils 10 and 10 are included in series in a circuit a, which circuit also includes a condenser 16. The two coils are so connected in this circuit that the potentials induced in these coils by an alternating current flowing in opposite directions in the two rails are additive, so that the vehicle governing current in the track rails will cause an alternating current to flow in circuit a. The coils 10 and 10 are so wound as to have high inductance while the condenser 16 has a comparatively small capacity, and these parts are so ad-.

j usted that.circuit a is tuned to resonance at the frequency of the vehicle governing current; it follows, therefore, that condenser 16 will be charged to a comparatively high potential by the comparatively feeble current induced in circuit a by the vehicle governing current in the track rails. This potential, is however, too feeble to reliably actuate traffic controlling apparatus of a rugged character, hence I have provided suitable amplifying apparatus, which, in the form here shown, comprises three electron tubes K, K and K Each of these tubes (see tube K) comprises a vacuum bulb 11 containing a filament 12, a plate 14, and a grid 13 interposed between the filament and the plate.

The filament 12 of the electron tube K is constantly heated by a battery 15, the circuit bein from the upper terminal of this battery, t rough wire 19, adjustable resist-. ance 17, filament 12, wire 48, adjustable re sistance 18, and wire 30 to the lower terminal of battery 15. The battery 15 may be a car lighting battery or a headlight generator, the potential of which is preferably about 32 volts.

The electron tube amplifier K is provided with a grid circuit which .passes from coil 10 through wires 20 and 20, grid and filament of tube K, wire 48, resistance 18, and wires 30 and 21 to coil 10 and coil 10. virtue of the adjustable resistances 17 and 18 in the filament and grid circuits of amplifier K, these circuits may be so adjusted that the potential of the grid 13 is always negative with respect to that of the negative end of filament 12, so that there will be no transfer of electrons between the grid and filament. The difference of potential between these two parts is preferably 1.5 volts.

An alternating potential impressed upon the grid and filament, due to circuit a, in excess of 1.5 volts will therefore permit the grid to become positive and permit a flow of electrons from the filament to the grid, thereby robbing the oscillating circuit of energy and hence limiting the value of the oscillating voltage to approximately 1.5 volts irrespective of the value of the track current, as long as the latter value is above the minimum which will induce 1.5 volts. Therefore the system will operate reliably and uniformly over a wide range of track currents above a predetermined minimum.

' The amplifier K is provided with a plate circuit which includes a separate battery 22 in series with battery 15, the total potential being preferably about 50 volts. The plate circuit of K is from the upper or positive terminal of battery 22, through wire 23,

rimary winding of a step-up transformer 5'. plate and filament of amplifier K, wire 48 resistance 18, wire 30, battery 15, wire 25 to battery 22. Connected in multiple with the primary of transformer J is a condenser 24, the local circuit which comprises this condenser and primar winding being tuned to resonance at the requency of the vehicle governing current. It will be seen from the foregoing that the minute variations of potential in the receiving circuit a will create variations of considerably greater magnitude in the strength of the current from battery 22 in the plate circuit of amplifier K.

The filaments of amplifiers K and K are connected in series and are supplied with current from battery 15, the circuit being from the upper terminal of this battery, through Wires 19 and 26, filament and am lifier K wire 27, filament of amplifier K wire 28, adjustable resistance 29, and Wire 30 to battery 15.

Amplifier K is provided with a grid circuit which passes from the upper terminal of the secondary of transformer J, throu h wire 31, grid and filament of amplifier wire 27, filament of amplifier K wire 28, adjustable resistance 29 and wire 32 to the lower terminal of the secondary of transformer J. The point of connection of wire 32 to resistance 29 is so chosen that the grid of K will be sufliciently'negative with respect to the negative end of the filament of K that there will be no transfer of electrons between the grid and filament. That is, this negative potential should equal or exceed the maximum potential of the secondary of transformer J. Under these circumstances the latter will operate under practically open circuit conditions and hence may have a high number of secondary turns, giving a very high voltage amplification.

The p ate circuit of amplifier K is supplied with direct current by the generator G of a motor generator set Z, the motor M of which is constantly supplied with current by the battery 15. The current delivered by generator G is preferably about 350 volts. The plate circuit for amplifier K is from the upper terminal of generator G, through wires 33 and 34, primary of a transformer J plate and filament of amplifier K wire 27, filament of amplifier K, wire 28, resistance 29, and wire 30 to the lower terminal of generator G. A condenser 24 is connected in multiple with the primary of transformer J the local circuit comprising this primary and condenser being tuned to resonance at the fre uency of the vehicle governing current. e ratio of transformer J is referably about one to two.

t follows then, that variations in the plate current of amplifier K will be reproduced as an alternating difference of otential in the grid circuit of amplifier Ix, resulting in similar variations of much greater amplitude in the current in the plate circuit of amplifier K Amplifier K is provided with a grid circuit which passes from the upper terminal of the secondary of transformer J throu 11 wire 35, grid and filament of amplifier and wire 36'to the lower terminal of the secondary of transformer J". The grid of amplifier K" is thus at the same potential as the negative end of the filament of K thus permitting a greater flow of current from the plate to the filament with a given plate to filament potential, and hence ermitting a greater output, than would be the case if the grid were made negative. It follows then that the variations in the plate current of amplifier K are reproduced as an alternating difference of potential in the grid circuit of amplifier K.

The plate circult of amplifier K includes the two stator windings 38 and 38 of an induction motor relay L, winding 38 being shunted by a condenser 39 to provide the proper phase displacement between the currents in these two windings. This late circuit passes from the upper termina of nerator G, through wires 33 and 37, win ing 38 and condenser 39 in multiple, winding 38, wire 40, plate and filament of amplifier K wire 28, resistance 29, and wire 30 to the lower terminal of generator G. With the apparatus proportioned substantially as set forth, the pulsations of the current thus supplied to the stator windings of the relay L will be of suflicient amplitude to actuate the rotor 41 of this relay reliably even though the relay be of a rugged commercial type. This relay may be constructed to operate on a normal energy of 3 watts.

The plate circuit of amplifier K is preferably energized from the battery 22 instead of from generator G, to avoid the possibility of the generator of alternatin current in this circuit from any source ot er than the track rails, since such current, even if of minute amplitude, would be amplified by tube K and K and might thus result in false operation of the system.

As here shown, the relay L controls a brake application ma net N and a cab signal S. The magnet controls the vehicle brakes in such manner that the brakes are applied when this magnet is de-energized.

, relay ernin The circuit for magnet N is from battery 15, through wire 19, contact 42 of relay L, wire 44, winding of magnet N, and wires 45 and 30 to batter 15. The contact 42 is closed when relay is energized, and, consequently, it will be seen that the magnet is energized whenever rela L is energized, that is, whenever the vehic e is supplied with vehicle govcurrent from the track rails. The cab signal S comprises a green lamp and a red lamp, which lamps indicate proceed and stop, respectively, when illuminated. These lamps are controlled by a contact 43 of relay L in such manner that the green or proceed lamp is illuminated when relay L is energized, and the red or stop lamp is illuminated when the relay is de-energized. The circuit for the green lamp is from battery 15, through wire 19, upper point of contact 43, wire 46, the green lamp, and wire 30 to battery 15. The circuit for the red lamp is the same, except that it includes the lower point of contact 43 and wire 47.

The operation of the entire apparatus as thus far described is as follows:

Referring again to Fig. 1, it will be seen that the block to the left of location A is occupied by a vehicle V, which vehicle I will assume is equipped with the governing apparatus shown in Fi 2. Inasmuch as track H is energized, vehicle governing current is supplied to the rails of the block to the left of location A, so that relay L on vehicle V is energized, with the result that the brake controlling magnet N is energized and the green or proceed lamp is illuminated. As the vehicle V enters block AB no change will occur in the vehicle carried apparatus, because this block is supplied with vehicle governing current due to the fact that rela H is energized. Block B-C is not supp ied with vehicle governing current, however, because contact 8 of track relay HP is open, due to the fact that the block to the right of location C is occupied by a vehicle V. As the vehicle V enters block BC, therefore, relay L will become deenerglzed, thereby extinguishing the green lamp, illuminating the red lamp, and deenergizing the brake controlling magnet N. The vehicle will, therefore, be brought to a stop or to a predetermined low speed, depending on the character of the apparatus interposed between magnet N and the braking system of the vehicle, If, while vehicle V is in block B-C, vehicle V passes out of the block to the right of location C, vehicle governing current will immediately be supplied to the rails of block B-C, so that relay L on vehicle V will immediately become energized, and this vehicle may then resume full speed.

Referrin now to Fig. 3, the apparatus shown in t is view is similar to that shown in Fig. 2, the chief difference being that in Fig. 3 the train controllin relay, which is here designated L, is of t edirect current type, and the output of the amplifiers is transformed into direct current by a rectifying device U, which device in turn supplies energy to the relay L. Another difference between the two views is that only two amplifiers K and K are employed in the apparatus shown in Fig. 3.

The filaments of the amplifiers K and K are constantly heated by current from battery 15, the circuit being from the upper terminal of this battery, throu h wires 19 and 139, filament of amplifier adjustable resistance 29, wire 141, filament of amplifier K, and wires 142 and 30 to batter 15. The grid circuit for amplifier" K is rom coil-10 through wire 143, battery 144, wire 145, grid and filament of amplifier K, wires 142 and 146 and coil 10 to coil 10*. The function of the battery 144.is to maintain the potential of the grid 13 negative with respect to the filament 12. The plate circuit of amplifier K is from battery 22, through wire 23', primary of transformer J and condenser 24 in multiple, wire 23, plate and filament of amplifier K, wires 142 and 30, battery 15, and wire 25 to battery 22. The secondary of transformer J supplies an alternating difference of otential to the grid circuit of amplifier this circuit being from secondary of transformer J, through wire 31, grid and filament of amplifier K wire 140, a portion of the adjustable resistance 29, and wire 32 to transformer J. The plate circuit for amplifier K is from generator G of the motor generator set Z, throu h wires 33 and 33, primary 147 of trans ormer J and condenser 154 in multipe wire 148, plate and filament of amplifier wire 140, resistance 29. Wire 141, filament of K, wire 142 to generator G. The local circuit including condenser 154 and the primary of transformer J is tuned to resonance at the frequency of the vehicle governing current. The armature circuit of generator G is preferably shunted by a condenser 149, as shown, in order to damp out the commutator, pulsations in the generator current. The rectifying device U comprises a transformer J 3 and two electron tubes K and K each of which is similar to the amplifiers K and K hereinbefore explained, and the filaments of which are constantly heated by virtue of a circuit which passes from the upper terminal of battery 15, through wires 19 and 150, resistance 29, wire 151, filament of tube K wire 152, filament of tube K, and wires 153 and 30 to battery 15. Transformer J 3 is provided with two secondaries 147 and 147", in series, whose outer terminals are connected to the wire 140,

plates of electron tubes K and K by wires winding of relay L by a wire 157. The circuit of secondary winding 147 is from its right hand terminal to wire 157, winding of L, wire 158, filament of K to plate, and wire 155 to winding 147. Since the electron tube possesses unidirectional conductivity, this circuit will in effect be open when the alternating potential across the transformer secondary is in such direction that the left hand terminal is negative, and will permit current to flow through the relay only when the left hand terminal is positive. The circuit of secondary winding 147 is from its left hand terminal to wire 157, winding of L, wire 158, filament of K, filament of K toplate, and wire 156 to winding 1 17 This circuit will evidently be effectively open when the right hand terminal is negative, and will permit current to flow through the relay onlywhen the ri ht hand terminal is positive. Windings 14 a and 14:7 therefore supply current to the circuit of L during alternate half cycles, andthe current through the winding of L is unidirectional.

In order to lower the effective internal impedance of the electron tubes and hence to increase the current through L, I connect the grid of K by wire 159 to a point onresistance 29 which is positive with respect to the filament of K and likewise connect the grid of K by a wire 160 to a point positive with respect to the filament of K.

It is understood that relay L may control suitable vehicle 'overning apparatus, such, for example, as t e apparatus shown in Fig. 2, and controlled by relay L in that view.

Referring now to Figs. 4, 4 and 4", I have here shown one form of trackway apparatus embodying my invention adapted for use in connection with a single track signaling system of the type known as absolute permissive block signaling. In this drawing, the reference characters 50, 50 designate the track rails of a stretch of single track over which traflic moves in both directions, and which stretch includestwo passing sidings 51 and 52. The rails are divided by insulated joints 49 to form a pinrality of sections 5354, 5455, vetc., and each section except the ones at which the passing sidings are located is further divided by similar insulated joints toform a plurality of sub-sections such as 54--54 and 54 55. Each sub-section is provided with a track circuit comprising a track battery D and a track relay designated by the reference character H with a suitableexponent, and each passing siding section 53--54= and 57- 58. .is provided with a similar .track circuit.

Trafiic along the stretch from west to east is governed b a plurality of roadside signals S S", 6 etc., while traific along the stretch from east to west is governed by a plurality of signals S, S, S etc. As here shown, each slgnal is located. adjacent the junction of two track sections, although this exact location is not essential. Each signal is of the three-position semaphore type, arranged to indicate stop, caution and proceed, according as the semaphore is in the horizontal, inclined or vertical position.

Each signal S is controlled by a line relay which is designated by the reference character R with the same exponent as that of the signal which it controls.

Each signal is provided with a caution circuit and a proceed circuit. Referring particularly to si al 8", the caution circuit is from one terminal B of a suitable source of current, through front point of contact 59 of relay R wire 60, operating mechanism of signal S, wire. 61, and contact 62 of relay R to the other terminal 0 of the same source of current. The proceed circuit is from terminal B through the front point of contact 59, wire 62, polarized contact 63 of relay R wire 64, and thence asbefore to terminal 0. It will be seen that this proceed circuit is closed only when relay R is energized in such direction as to close contact 63, which direction I will term the normal energization of this relay.

The control circuits for each of the sig nals are similar to those for signal S", and hence they need not be traced in detail herein. a

The line relay R for signal S is provided with a circuit which passes from terminal B (see Fig. 4) of a suitable source of current, through a pole-changer P operated by signal 8, Wires 65 and 66, contact 67 of relay R wires 68 and 69, contact 70 of track relay H wire 71, contact 72 of track relay H wire 73, winding of relay R common wire 0, wire 74 and pole-changer P to terminal O of the same source of current. This circuit, then, is controlled by track relays H and H and by the line relay R for signal S.

Line relay R for signal S is similarly controlled by line relay R and by track relays H and H the circuit also including a back contact 75 of a. relay X which relay is referred to hereinafter. Line relay R for signal S is controlled by track relays H and H and by a pole-changing relay W the control of which is explained hereinafter.

I When relay W is energized, the circuit for signal relay R is from terminal B of a suitable source of current through the front point of contact 76 of relay W", wire 77,

contact 78 of relay H, wire 79, back contact rent supplied to the latter relay is then reversed due'to the factthat the contacts of rela W constitute a pole-changer.

T control of relay W Will be explained hereinafter.

Relay R which controls signal S is provided with a circuit which is as follows:

From terminal B of a suitable source of current through pole-changer P operated by signal S wire 87, contact 88 of track relay H wire 89, contact 90 of track relay H wire 91, winding of relay R", wires 92, 93 and 94, pole-changer P to terminal 0 of the same source of current. Relay R is energized in the normal direction when signal S indicates proceed or caution, and in the reverse direction when signal S indicates stop.

Relay R 1 which controls signal S, is controlled by apparatus in the stretch to the left of the passing siding 51, which apparatus is similar to the apparatus hereinbefore explained for the control of relay R The circuit for relay R is provided with a shunt around contact 67 of relay R", which shunt passes from wire 65, throu h wire 95, contact 96 of an auxiliary relay and Wire 97 to wire 69. Relay 5 is provided with a pick-up circuit which passes from terminal B of a suitable source of current, through contact 98 operated by si nal S wire 99, back contact 100 of track re ay H wire 101, winding of relay X wire 102, back contact 103 of relay R to terminal 0 of the same source of current. This circuit can be closed only when signal S is in the proceed or caution position, track relay H is open and line relay R is open, and consequently, it follows that relay X can be picked up only when a train moving toward the left passes signal S". Relay X is provided with a holding circuit which passes from terminal B of a suitable source of current, through contact 104 of relay X wire 105, winding of relay X wire 102, and back contact 103 of relay R to terminal 0 of the same source of current. It follows, therefore, that when relay X is once closed it will remain closed as long as line relay R remains open.

' Relay R is at times removed from control by relay R through the medium of an auxiliary relay same manner as relay X.

In so far as the control of the roadside signals is concerned, it remain only to consider the circuits for the pole-changer relay W". This relay is provided with a circuit which passes from terminal B of a suitable source of current. through contact 106 operated by signal S, wires 107, 108 and 109, contact 110 operated by signal S, Wire 111, winding of relay \V, wires 112, 92, 93 and94, and pole-changer P to terminal 0 of the same source of current. It will be X which operates in the seen, that, so far as this circuit is concerned, whenever signal S indicates stop, relay S" will indicate caution. Relay W is provided with a branch around signal operate contact 106, which branch is controlled by the auxiliary relay X and which latter relay is in turn controlled in the same manner as relay X The branch passes from battery terminal B, through contact 113 of relay X and wires 114 and 115, to wire 108. When a train moving toward the left passes signal so that relay W is removed from control by contact 106, whereupon this relay closes and permits signal S to assume the proceed position.

Signals s s St,

the same manner as the westbound signals, and consequently a detailed explanation of the circuits for the eastbound signals is unnecessary.

The operation of the system in so far as the trackway signals are concerned is in accordance with standard and usual practice, and hence a detailed explanation is not required. It should be noted, however, that an eastbound train in the stretch of track to the west of siding 51 causes both signals S and S to assume the caution position, but that a westbound train in the same stretch of track permits signal S to return to the proceed position as soon as signal S returns to the caution position. The reason for this selective control of the caution aspect of signal S is well understood.

Each track section and sub-section is provided with means for supplying alternating vehicle governing current to the rails of the section at both ends. Considering sub-section 55--56, for example, this current is supplied to the battery end through the medium of a transformer T the secondary of which is included in the track circuit between the battery D and one rail, and the rimary of which is at times supplied, as explained hereinafter, from a transmission line Q, which in turn is connected with a suitable source of alternating current not shown in the drawings. At the relay end of this sub-section the vehicle governing current is furnished by a transformer T, the primary of which is likewise supplied at times from transmission line Q, and the secondary of which is connected across the rails of the section in multiple with track relay H A resistance 116 is'included between the secondary of transformer T and one track rail to prevent the transformer from forming a low-resistance shunt across the relay H Each track section is supplied with vehicle governing current in the same manner as sub-section 55 56.

The supply of vehicle governing cu rent W will be deenergized so that signal etc., governing trailic from west to east, are controlled in exactly.

to the track rails is controlled as follows: Considering section 55-56, the supply of current to transformer T at the west end of sub-section 55 -56, and to transformer T at the west end of sub-section 55-55 is controlled by a contact 117 operated by signal S", which contact closed when this signal is at proceed or caution, but open the signal is at stop. The circuit for transformer T is from the upper wire of transmission line Q, through wires 118 and 119 contact 117, wires 120 and 121, primary of transformer T and wires 122 and 123 to the lower wire of transmission line Q. Transformer T is connected in multiple with transformer T the branch being from wire 120 through wire 124, primary of transformer T and wires 125 and 126' to the lower wire of transmission line Q. It will be seen, therefore, that vehicle governing current is supplied to the west end of each sub-section of section 55-56 if signal S indicates roceed or caution, but not if this signal indicates stop. In similar manner, the transformer at the east end of each subsection in section 55-56 is controlled by a contact 117 operated by eastbound signal 8". As for section'54-55, the transformers T and T, which may be termed the eastbound transformers, are controlled by contact 117 of eastbound signal S, but the westbound transformers T and T for this section are controlled b a front contact 127 of pole-changing relay iv. Considering now the passing siding section 53-54, the eastbound transformer T for this section is controlled by contact 117 on the eastbound signal S, and the westbound transformer T for this section is controlled by contact 127 operated by signal S". The transformers for section 57-58 are controlled in the same manner as those for section 53-54.

I will now assume that a car or train equipped with the apparatus shown in Fig. 2 or Fig. 3, passes along the track shown in Fig. 4. It will be vobvious that whenever such train occupies a section immediately in the rear of signal indicating proceed or caution, a proceed indication will be given aboard the train, but that when the train passes a caution signal the supply of vehicle governing current will be discontinued so that a stop indication will be given on the train, which if desired, may be employed to control the speed of the train so that it will be brought to a stop at the next signal. Assuming then that a westbound train comes to a stop in section 55-56, and that a following westbound train equipped with the apparatus shown in Figs. 2 or 3 passes along the track, it will be seen that the latter train will receive a stop indication immediately after passing signal S, because signal S will be at stop.

I will now assume that the stretch of track to the west of siding 51 is occu ied by a train moving toward the east. ignal S then indicates stop, while signals S and S both indicate caution. If now a westbound train enters the stretch between sidings 51 and 52, this latter train will receive a proceed indication throughout section 56-57, a proceed indication throughout sections 55-56, but-a stop indication immediately after passing signal S because pole-changer relay W is open, so that the supply of vehicle governing current to transformers T and T is discontinued at contact 127. It follows that this westbound train will be brought to a stop or to a low speed in section 54-55, whereupon it may pass signal S and enter the passing siding 51 under control. I will now assume thata westbound train occupies the second sub-section to the west of siding 51, that is, the sub-section corresponding to 56-56, and that a second westbound train enters the stretch between sidings 51 and 52. Signal S now indicates stop, signal S" indicates caution and signal S indicates roceed because the polechanging relay V6 is closed. The second westbound train, therefore, receives a proceed indication throughout section 54-55, but it receives a stop indication immediately after passing signal S.

The apparatus shown in Figs. 4, 4' and 4 and thus far referred to would operate in a satisfactory manner except under one condition; namely, when an eastbound train enters the stretch to the west of siding 51 after a westbound train has passed signal S at proceed and has entered section 54- 55. This eastbound train would cause signal S to move to the stop position, so that pole-changing relay W would open, thus cutting off. the supply of vehicle governin 1 current to the train which is moving toward the west in section 54-55. In other words, this latter train would have entered section 54-55 under a proceed indication at signal S" and would then receive an unexpected and unnecessary stop indication before reaching signal S". This is particularly disadvantageous in train control systems in which the engineer is penalized for failure to observe signals, and is required to acknowledge stop or caution signals in advance of the change in the indication of the train controlling apparatus in order to avoid some sort of penalt To avoid this, I have provided means relay W closed after a westbound train passes signal S, provided that it is closed when the train passes this signal. This means comprises a relay L which serves as a repeater for stick relayX. The circuit for relay L is from terminal B of a suitable source of current through pole-changer P, wires 127, 128 and 129, contact 130 of or keeping the pole-changing westbound train passes relay X, wire 131, winding of relay L, wire 132, common wire 0, wire 133 and pole-,

changer P to terminal 0 of the same source of current. It follows, therefore, thatirelay L will be energized when relay X is closed. This latter relay is, of course, closed b a westbound train passing signal S, provided that such signal then indicates proceed or caution. \Vhen relay L is closed it closes a stick circuit for rela W", which circuit is from battery termina B, through pole-changer P wire 87, contact 88 of track rela H, wire 89, contact 90 of track relay wires 91 and 138, contact 137 of relay W", wire 136, contact 135 of relay L, wires 134 and 109, contact 110, wire 111, winding of relay W and wires 112, 92, 93 and 94, through pole-changer P to battery terminal 0. It will be seen, therefore, that when relays W and L are closed, the openin of contact 106 o erated by signal S wil not cause relay 9 to open. When a signal S under a proceed indication, therefore, this train will continue to receive a proceed indication until it reaches signal S, even though an eastbound train may in the meantime enter the stretch of track to the west of siding 51. On the other hand, if the westbound train should remain in section 54-55 until the eastbound train traversed the entire section to the left of signal S and the eastbound train should pass signal 8*, it is evident that sufiicient braking distance no longer exists to permit the two trains to approach each other at speed. Under these conditions the eastbound train will receive a stop indication upon passingrsignal S at caution, because transformer 3 iscut off b circuit controller 117 open with signal at stop, while the westbound train will receive a stop indication wherever it may be in section 54- 55 because signal S will go to stop opening the holding circuit of W at circuit controller 110, thus de-energizing W and opening the circuit of transformer T.

Although I have herein shown and described only certain forms of apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. Railway trafiic controlling apparatus comprising a plurality of successive blocks, a track circuit for each block comprlslng a source of direct current and a track relay, a transformer for each block whose secondary is included in the connection between one track rail and said source, and means for each block controlled by the track relay for the block next in advance for supplying vehicle governing alternating current to the nected across primary of the transformer for the block when such track relay. is energized but not when the track-relay is deenergized.

2. Railway tl'aflic controlling apparatus comprising a plurality of successive blocks, a track circuit for each block comprising a source of direct current anda track relay, and means for each blockcontrolled by the track relay for the block next in advance for supplying vehicle governing alternating current to the track rails of the block in series with said source of direct current when such relay is energized but not when the relay is de-energized.

3. Railway traflic controlling apparatus comprising a plurality of successive blocks, a track circuit for each block comprising a source of track circuit current and a track relay, and means for each block controlled by the relay for the block next in advance for supplying vehicle governing current differing in character from the track circuit current to the rails of the block in series with the source of track circuit current.

L'Railway trafliccontrolling apparatus comprising a plurality of successive blocks,

a track circuit for each block comprising a source of track circuit current and a track relay, and means for each block controlled by the relay for the block next in advance for supplying vehicle governing current differing in character from the track circuit current to the rails of the block in series with the source of track circuit current, a

vehicle, and vehicle governing means thereon receiving energy from the track rails and responsive to the vehicle governing current but not to the track circuit current.

5. In combination, a stretch of railway track over which trafiic moves in both directions, a track circuit in said stretch comprising a track battery and a track relay connected across the rails at different points, roadside signals for said stretch controlled by said relay, two sources of vehicle governing current connected across said rails adjacent said battery and said relay respectively, and means controlled by a car or train approaching said track circuit for disconnecting from the rails the source of vehicle governing current nearest to such car or train.

6. In combination, a stretch of railway track over which traflic moves in both directions, a track circuit in said stretch comprising a track battery and a track relay conthe rails at different points, roadside signals for said stretch controlled by said relay, two sources of vehicle governing current connected across said rails in series with said battery and in multiple with said relay respectively, said latter connection including a resistance, and means controlled by a car or train approaching said track circuit for disconnecting from the rails tions, a track circuit in said stretch com-' prising a source of track circuit current and a track relay connected across the rails at different points, two sources of vehicle overning current differing in character roin the track circuit current and connected across the rails adjacent the two ends of said track circuit, and means controlled by a car or train approaching said track circuit for disconnecting from the rails the source of vehicle governing current nearest to such car or train.

8. In combination, a stretch of railway track over which traflic moves in both directions, means for dividing said stretch into a pluralit of sections and for dividing each section into two sub-sections, signals located adjacent the junctions of adjacent sections for governing traflic through said stretch in both directions, a trackcircuit for each subsection comprisin a battery at the end nearest the middle 0 the whole section and a track relay at the other end of the sub-section, a line relay for each signal, means for normally controlling each line relay by the track relays for the section through which the corresponding signal governs traflic and by the line relay forthe signal next in ad- Vance governing traffic in the same direction, means for .at times removing each line relay from control by the line relay by which it is normally controlled, means for each sub-section for normally supplying vehicle governing current to the rails thereof at each end, and means controlled by each line relay when de-energized for disconnecting from the two sub-sections in the rear of the corresponding signal the vehicle governing current which is normally supplied to the ends ofsuch sub sections nearest to such signal.

9. In combination, a stretch of railway track over which traffic moves in both directions, signals governing trafiic in one direction through said stretch and other signals governing traflic in the other direction through said stretch, a line relay for each signal, means for normally controlling each line relay by the line relay for the signal next in advance governing traflic in the same direction, means for at times removing each line relay from control by the line relay by which it is normally controlled, track cir cuits for the stretch for controlling said line relays, means for supplying vehicle governing current to the rails of each track circuit at both ends thereof, and means controlled by each line relay when de-energized for disconnecting from the track circuit immediately in the rear of the corresponding signal the vehicle governing current which is normally supplied to the end of such track circuit nearest to such signal.

10. In combination, a stretch of railway a signal for the first section, a relay for said signal for causing the signal to indicate proceed or caution according as the relay is track divided into three successive sections,

closed or open, means controlled by said relay for supplying vehicle governing current to the rails of the first section when the relay is closed but not when the relay is open, means for normally opening said relay when a train enters the third section moving towards the first and means for preventing the opening or said relay due to a train entering the third section moving towards thefirst when a train occupies the first section moving towards the third until the train in the third section enters the second section.

11. In combination, a stretch of railway track comprising three successive sections, means for supplying vehicle governing current to the rails of the first section when the other two sections are unoccu ied to permit a train to move through the fi rst section towards the third, and for normally preventing such supply when a train enters the third section moving towards the first, and means for preventing the discontinuance of said supply of current due to a train entering the third section moving towards the first while a train occupies the first section movin towards the third.

12. n combination, a section of railway track, a track circuit for the section including a battery connected across the rails of the section, a transformer the secondary of which is included in the connection between said battery and one of the track rails, and means for supplying alternating vehicle governing current to the primary of said transformer.

13. In combination, a stretch of railway track comprising two blocks'separated by a passing siding, one block having an insulated section adjacent to said siding, means for supplying vehicle governing current to said section when the second block is unoccupied to permit a train to pass through the section towards the passing siding and for normally preventing the supply of such current when a train enters the second block moving towards the siding, and means controlled by a train in said section moving towards the siding for preventing the discontinuance of the supply of current to such section due to a train entering the second block.

14;. In combination, a stretch of railway track comprising two blocks separated by a passing siding, the first block having an insulated section adjacent to said siding, a relay for said section, means controlled by a train inthe second block moving toward said siding for preventing said relay from closing, means controlled by a train in said section moving towards the siding for preventing said relay from being opened by a train entering the second block moving towards the siding, and means controlled by said relay when closed for supplying vehicle governing current to said section to permit a train to move through the section towards said siding.

15. In combination, a stretch of railway track comprisin two blocks separated by a passing siding, t h sulated section adjacent said siding, a stick relay for said section, a pick-up circuit for said relay opened by a train in the second block moving towards the siding, a holding circuit for said relay closed while a train is in said section moving towards the siding regardless of the entrance of a train into the second block provided said relay is closed when the train enters said section, and means controlled by said relay when closed for supplying vehicle governing current to said section to permit a train to move through the section towards said siding.

16. In combination, a stretch of railway track comprising two blocks separated by a passing siding, the first block being provided with an insulated section adjacent said siding, a relay, means for opening said relay when a train enters the second block moving towards the first and for holding it open until such train leaves the second block, a second relay, a pick-up circuit for said second relay controlled by a front contact of the first relay, a holding circuit for said second relay including a front contact of the second relay and a contact closed by a train in said section moving towards the siding, and means controlled by said second relay when closed for supplying vehicle governing current to said section.

17. In combination, a section of railway track, a track circuit for the section including a relay connected across the track rails, a transformer the secondary of which is 7 connected across the rails of said section in multiple with said relay, means interposed between said relay and said secondary for preventing the secondary from shunting the track circuit current away from the relay, and means for supplying alternating vehicle governing current to the primary of said transformer.

18. In combination, a section of railway track, a track circuit for the section including a relay connected across the track rails, a transformer the secondary of which is connected across the rails of said section in multiple with said relay, a resistance interposed between said relay and said secondary, and means for supplying alternating vehicle governing current to the primary of said transformer.

e first block having in in- 19. In combination, a section of railway track, a direct current track circuit for said section including a track relay connected across the track rails, a transformer the secondary of which is connected across the track rails of said section in multiple with said relay, means interposed between said relay and said secondary for preventing the secondary from shunting the track circuit current away from the relay, and

means for supplying alternating vehicle governing current to the. primary of said transformer.

20. In combination, a section of railway track, a track circuit for said section including a source of current and a track relay, a transformer the secondary of which is included in the connection between said source of current and the track rails, a second transformer the secondary of which is connected across the rails of said section in multiple with said relay, and means for supplying alternating vehicle governing current to the primaries of said transformers.

21. Incombination, a section of railwa track, a track circuit for said section inclu ing a battery and a track relay, a transformer the secondary of which is included in the connection between said battery and the track rails, a second transformer the secondary of which is connected across the rails of said section in multiple with said relay, means interposed between said second secondary and said relay for preventing the secondary from shunting direct current away from the relay, and means for supplying alternating vehicle governing current to the primaries of said transformers.

22. In combination, a section of railway track, a source of vehicle governing current connected across the rails of said section, and a track circuit for said section including a source of current interposed in the connection between said first source and a track rail and differing in character from such first source.

23. In combination, a section of railway traclr, two sources of vehicle governing current connected with the rails of said section adjacent the ends of the section respectively, and a track circuit for said section including a source of current differing in character from said vehicle governing current and a track relay responsive to said track circuit source.

24. In combination, a stretch of railway track divided into a plurality of successive sections, a track circuit for each section including a source of current and a track relay connected across the rails, a trans: former for each section the secondary of which is interposed between the source of current for the section and a track rail of the section, and means controlled by each track relay for supplying alternating vehicle governing current to the primary of the transformer for the adjacent section.

25. In combination, a stretch of railway track divided into a plurality of successive sections, means for supplying vehicle governing current to each end of each section,

and a track circuit for each section includ-.

ing a source of current of distinctive character and a track relay for controlling the suply of vehicle governing current to the adacent end of each of the adjacent sections.

26. In combination, a stretch of railway track divided into a plurality of successive sections, a track circuit for each section, and means controlled by each track circuit for supplyin vehicle verning current distinctive in ciiaracter i l hm the track circuit current to the adjacent end of each adjacent section.

27. In combination, a section of railway track, atrackcircuit for the section including a relay connected across the track rails, a transformer the secondary of which is connected across the rails of said section in multiple with said relay, and means for supplying alternating vehicle governing current to the rimary of said transformer.

28. In combination a section of railway track, a track circuit for said section including a source of direct current and a relay, a transformer the secondary of which is connected across the rails of said section, means for supplying alternating vehicle governing current to the primary of said transformer, and means interposed between said secondary' and; said track rails for limiting the amount of direct current shunted from said relay by said secondary.

29. In combination, a section of railway track, a track circuit for said section including a source of direct current and a relay, a source of alternating vehicle governing current connected across the rails of said section, and means interposed between said alternatin current source and the track rails for limiting the amount of direct cur rent shunted from said relay by said alternating current source.

30. In combination, a stretch of railway track divided into sections, a track circuit for each section including a source of direct current and a track relay, means for each section for connecting a source of alternating vehicle governing current with the rails of the section when the track relay for the section next in advance is energized, a receiving circuit on a vehicle including a coil' in inductive relation to a track rail and also including a capacity device whereby the circuit is tuned to resonance at the frequency of said alternating current, and governing means on said vehicle shunted by said capacity device.

31. In combination, a stretch of railway track divided into sections, a track circuit for each section including a source of direct current and a track relay, means for each section for connect-ing a source of alternating vehicle overning current with the rails of the section when the track relay for the section next in advance is energized, a receiving circuit on a vehicle including a coil in inductive relation to a track rail and also including a capacity device whereby the circuit is tuned to resonance at the frequency of said alternating current, an amplifier on said vehicle having an input circuit shunted by said capacity device, and vehicle governing means controlled by the output circuit of said amplifier.

32. In combination. a stretch of railway track divided into sections, a track circuit for each section including a source of direct current and a track relay, means for each section for connecting a source of alternating vehicle governing current'with the rails of the section when the track relay for the section next in advance is energized, a receiving circuit on a vehicle including a coil in inductive relation to a track rail and also including a capacity device whereby the circuit is tuned to resonance at the fre- 

